On Wed, May 10, 2023, at 5:21 PM, Lennart Poettering wrote:
So to add to this. I happen to be at LFSMMBPF at the moment, the Linux File System summit (among other things) where all the Linux FS people meet. I spoke to a couple of FS maintainers here, and well, let me make this very clear: using any of the major Linux file systems with drivers that are not the ones in the Linux kernel is a very bad idea, and expressly not supported by them. [They actually used much harsher words, that I'll not repeat here – this is the "friendly" version of their take on your idea.]
So, unless you want to go against what the people who actually maintain the file systems expressly say please just get this idea out of your head that porting Linux file systems into EFI fs drivers was a good, supportable idea.
And Neal, Chris, if you don't believe the above, then hey, I am happy to open a thread with them in CC where they can tell you in person how bad an idea that is.
I don't know what question you asked them. Any modifications (writes) performed outside kernel code is not supported, since forever.
Read-only drivers, which are the only drivers under discussion here, aren't a per se problem because they can't modify the file system. So they have no complaints about that.